campbell



D. E. CAMPBELL, OF BOSTON, MASSACHUSETTS.v Leners Patent No. 64,281, ma Api-tz so, 1867.

IMPROVED ATTACHMENT FOR DOOR-KEYS.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, D. E. CAMPBELL, of Bost-on, Suffolk county, and State of Massachusetts, have invented a new and improved Safety Attachment for Keys ot' Doors, and I do herehydeclare that the following is a full, clear, and exact description thereof, which wilt enable others skilled in the art to make and use the same, l

reference being had to the accompanying drawing, forming partof this specification.

The present invention relates to a new and improved safety attachment for the keys of doors, the object and purpose of which is to enable the key cfa door to be so fastened or secured in the key-hole of the door, and within the lock, that it can be neither turned around Within or pushed or thrown out of the same from the opposite side of the door, whereby the picking of the lock. is not only prevented, but the insertion of another key for unlocking it also rendered impossible, the advantages and importance of which are obvious. In accompany ing plate of drawings my improved safety attachment for the keys of doors is illustrated- Figure 1 being a top vien' of the safety attachment, showing it as applied to the handle or knob, and the key of a door-lock; and i Y Figure 2, a front View of the same.

Similar letters of reference indicate like parts. v

A, in the drawings, represents my improved safety attachment embraced in the present invention, and it consists of a straight bar, B, or'stripof metal, or other vsuitable material, which, at or near'one end, C, is twisted, and terminates in t-Wo similar bent or circular-shaped spring-jaws or arms D D, the ends F of which jaws are at a short dista-nce from each other, as plainly shown by dotted lines in tig. 2. The twist of the barB such that its width and the Width of its spring-jaws or arms are in planes at a right angle to each other, the width ot the bar, when the attachment is applied to the key of a door-lock, as will be hereinafter ekplained,y being ini ay vertical plane, and that of the spring-jaws in a horizontal plane, the obj ect of which is to enable the attachment to be used upon keys that are either upon the right or left of the door-knob. G, a clasp or slide arranged upon the bar B so as to move or slide forward and backward thereon,to which slide a spring-catch, H, is attached, having a bent square-shaped recess, I, to receive the outer end of the sha-nk of a lockkey.

In the application ot' my safety attachment, above explained, to the keys of door-locks, the bar is first passed through the open end of the key-shank, with its spring-arms toward the doer-knob or handle, over the shank of which they are then sprung, and the clasp G slid or moved in the proper direction upon the bar B to interlock the sqnareshaped recess of its spring-catch H with the outer ond of the key-shank, as plainly shown in the drawings, when, as is obvious, the turning of the key from the opposite side of the door or its lock, or to push or throw .ont the key from the lock, is utterly impossible, thereby rendering the lock secure against being picked, er being unlocked by the insertion ofa key therein from the opposite side to that upon which the key is fastened in-the lock as above described, the advantages of which are manifest, my improved safety attachment being exceedingly cheap, simple, effective, and convenient for adjustment and use.

I claim as new, and desire to secure by Letters Patent- A safety attachment for. the keys of doors, consisting of a bar, B, having spring-arms or jaws D D, and av Spring-sliding catch, G, when arranged and combined together, and so as -to be used and to operate .substantially in the manner described.

D. E. CAMPBELL.

Witnesses:

JOHN S. DUDLEY, A. H. RAnsDELT.. 

